Method of repairing cracked metallic castings



c. B. HARRIS 3,464,103

METHOD OF REPAIRING CRACKED METALLIC CASTINGS Sept. 2, 1969 Filed July 13, 1967 s 0' R R A H N B N O E L C FIG. 2.

United States Patent O 3,464,103 METHOD OF REPAIRING CRACKED METALLIC CASTINGS Cleon B. Harris, 1732 Sherwood Forest Blvd, Baton Rouge, La. 70815 Filed July 13, 1967, Ser. No. 653,193

Int. Cl. 1323p 7/04; B22d 19/10; B231; 31/02 US. Cl. 29-402 3 Claims ABSTRACT OF THE DISCLOSURE A method of making cold repair on cracked or broken machine parts or pressure vessels of cast or forged metals where the crack or break occurs at an inside corner of the piece to be repaired. The method involves excavating metal from the corner of the piece and subsequent insertion of a metal angular repair member at the corner site of the crack or break. The angular repair member is then secured in-place by means of screws, wedges, or the like.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to new and useful improvements in methods of repairing cracked or broken metallic castings by non-thermal means.

Description of the prior art Heretofore, when fractions occurred at a corner of a casting or forged piece, the fracture radiating outwardly from the inside corner, it was practically impossible to repair the piece so that it would withstand the stresses for which the piece was originally designed. This was particularly true in pressure vessels and industrial pumps. As a consequence, expensive equipment had to be completely discarded due to the inherent dangers of placing it under operating pressures. With the method, hereinafter described, the present disadvantages are overcome and the fractured casting may be repaired to substantially restore it to its original condition.

SUMMARY OF THE INVENTION I have invented a novel method of repairing metal castings having fractures radiating from inside corners thereof which comprises forming two grooves in the casting, the grooves intersecting at the corner containing the fracture, thus defining an L-shaped depression at the castings cracked corner, thereafter inserting a rigid, metal angular repair member conforming to the size and angle of the grooves, forming a plurality of spaced Openings, circular in X-section, around the perimeter of the inserted repair member in such a manner that each opening lies half in the repair member and half in the casting, and then filling the opening with a bonding metal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings wherein an example of the invention is shown, and wherein:

FIGURE 1 is a plan view of a portion of a casting, having a fraction radiating from a corner thereof, having been repaired by the method of the invention,

FIGURE 2 is an enlarged, transverse, vertical, sectional view taken on the line 22 of FIGURE 1,

FIGURE 3 is an enlarged, isometric view of the repaired casting of FIGURE 1, and

FIGURE 4 is an isometrical view of the insertable repair member illustrated in place in FIGURES l, 2 and 3.

In the drawings, the numeral 10 designates a casting or other member having a fracture or crack 15 radiating from an inside corner therein. In carrying out the novel process of the present invention, a groove is cut in the casting 10 so as to define the configuration of the repair member, or L-shaped bar 12 shown generally in FIG- URE 4. The repair member 12 is shown placed in the groove cut from casting 10 in FIGURE 2. The groove ends are tapered outwardly to provide the repair member 12, having its ends 22 tapered in a like manner, easy access to the groove.

Subsequent to cutting the grooves in casting 10 and inserting repair member 12 therein, openings 13 are drilled so that the opening 13 lies half in the repair member 12 and half in the casting 10. The openings 13 are drilled around the perimeter of the repair member 12, as shown generally in FIGURES 1 and 3. The depth and spacing of the openings 13 is illustrated at B and A in FIGURE 2. In particular, the distance A, between openings 13-, is preferably at least equal to the radius of the circular opening 13. The distance B should preferably be at least half the depth of the opening 13. Particularly, the opening 13 should be drilled no more than two-thirds the thickness of the repair member 12.

The openings 13 should not be interconnected by means of grooves or other excavation. The strength and integrity of the repaired casting 10 is dependent upon the openings 13 being spaced A in the manner shown in FIGURES 1, 2 and 3.

By the nature of the drilling tool, the bottoms of the opening 16 contain slight depressions. It has been found that this configuration aids the bonding strength of the casting repair process of the invention.

To bond the repair member 12 to the casting 10 the drilled out openings 13 and 16 are filled with a bonding metal. When the filling step is completed, the surface of the repaired casting 10, as depicted in FIGURE 3, is finished off to furnish a smooth surface. It is particularly important that an opening 18 be located at the intersection of the two sides of the repair member 12. Consequently, the smoothing operation will make a V-shape configuration at the face of opening 18.

FIGURE 1 illustrates the repaired casting 10 with the angular bar repair member 12 in place. Opening 11 further demonstrates the bonding positions of the openings 11 and 13 being half in each the repair member 12 and the casting 10. The repair member 12 is set substantially well within the casting 10 being repaired. The bottom 14 of the repair member 12 is as substantially shown in FIGURE 1.

For certain applications it is desirable to have a reinforcing piece 17 attached to the repair member 12. The reinforcement is optional and depends entirely on the particular casting being repaired.

In drilling the openings 13 and 16, it is preferable to angle the openings 13 about 45 degrees from the inside face of the casting. This is particularly illustrated in FIGURE 2, wherein the openings 13 and 16 lie at about 45 degrees to the face of the casting 10. It will be noted that the terminal ends of the grooves, the ends 22 of the repair member, and the openings 13 are all slanted at the same angle for maximum bonding strength.

Other modifications of this invention will be readily apparent from the foregoing description of several preferred embodiments and it should be understood that the true scope of this invention is defined by the appended claims.

I claim:

1. A method of repairing castings having fractures radiating from inside corners thereof which comprises forming at least two grooves in the casting, the grooves intersecting at the corner containing the fracture, thus defining an L-shaped depression thereat, thereafter inserting a rigid, metal angular repair member conforming to the size and angle of the grooves, forming a plurality of spaced openings slanted at an angle of about 45 de grees to the respective face of the casting around the 5 perimeter of the inserted angular repair member in such a manner that each opening lies half in the angular repair member and half in the casting, and subsequently filling the openings with a bonding metal.

2. The method of claim 1 wherein the spaced openings are circular in cross-section and are spaced apart a distance equal to the radius of the openings.

3. The method of claim 1 wherein the spaced openings are formed to a depth at least two-thirds the depth of the grooved depression.

4 References Cited UNITED STATES PATENTS 2,278,334 3/1942 Scott 29-402 X 2,537,533 1/1951 Ingalls 29-402 FOREIGN PATENTS 764,622 12/ 1956 Great Britain. 987,055 3/ 1965 Great Britain.

JOHN F. CAMPBELL, Primary Examiner -D. C. REILEY, Assistant Examiner US. Cl. X.-R. 

